Endothermic ReactionSolid barium hydroxide octahydrate (Ba(OH)2*8H2O) and ammonium thiocyanate (NH4SCN) are mixed in a beaker, which is then placed on a few drops of water on a small board. The reaction that occurs is highly endothermic.

Sulfuric Acid into Water and IceWhen sulfuric acid is mixed with water the temperature rises. When sulfuric acid is added to ice, the temperature rises at first, but as the ice melts, the temperature falls.

SolutionsReactions and demonstrations exploring the concepts of solutions.

Noncovalent Interactions |

Physical Properties |

Precipitation / Solubility |

Solutions / Solvents |

Calorimetry / Thermochemistry |

Applications of Chemistry |

Acids / Bases |

Aqueous Solution Chemistry |

pH |

Conductivity |

Reactions |

Titration / Volumetric Analysis |

Liquids |

Solids |

Equilibrium |

Transport Properties

Crystallization of Supersaturated Sodium AcetateA supersaturated solution of sodium acetate is poured onto one small sodium acetate crystal. Crystals form from the liquid immediately upon contact with the seed crystal. A thermometer shows that the crystallization process is exothermic. A chemical hot pack is shown as an example of a commercially available supersaturated solution.

Precipitation / Solubility |

Solutions / Solvents |

Calorimetry / Thermochemistry

TNT DetonationTNT is stable in the presence of shock, but can be detonated by adding a chemical priming agent.

Oxidation / Reduction |

Thermodynamics |

Aromatic Compounds |

Reactions

EntropyThese processes are shown in reverse. The situations shown are so highly improbable that we would not expect to observe them in nature.

Exploding Soap Bubbles: Hydrogen + OxygenA series of three videos shows that as the ratio of oxygen to hydrogen in soap bubbles increases, the explosions that occur when the bubbles are ignited get louder. (The fact that with an excess of oxygen the explosions would become softer again is not shown.) Each video is repeated with no voice-over so that only the sounds of the explosions are heard. Five still images are provided to show the stoichiometry on the molecular scale. The videos are intended to be shown in order beginning with Hydrogen Alone and ending with hydrogen plus more oxygen.

Reaction, Microscale: Potassium Dichromate with Silver NitrateA crystal of potassium dichromate is carefully combined with a solution of silver nitrate under a microscope. The reaction takes some time, so it is shown in a series of seven sequential videos. To see the entire reaction you need to play all seven.

Combustion of MethaneMethane combustion in balloons, a Bunsen burner flame, and methane combustion in chlorine are demonstrated.

Alkanes / Cycloalkanes |

Reactions

Combustion of HexaneCombustion of hexane with limited oxygen and addition of water to burning hexane are demonstrated.

Alkanes / Cycloalkanes |

Reactions

Bromination of HydrocarbonsThe light initiated bromination of pentane, hexane isomers, alkyl benzenes and a comparison of bromination of pentane and pentene are demonstrated.

Alkanes / Cycloalkanes |

Reactions

Diels-Alder VisualizationSeveral computer animations of a Diels-Alder reaction that were created as an undergraduate student project are presented.

Addition Reactions |

Alkenes

Addition Reactions of AlkenesThe Diels-Alder reaction, addition of oxygen to tetrakis(N, N-dimethylamino) ethylene, polymerization of ethylene, and addition of iodine to a-pinene are demonstrated. Molecular models of ethene are shown.

Hydrogen + Chlorine CannonWhen a corked test tube containing a mixture of hydrogen and chlorine is struck by light from a burning magnesium ribbon, the resulting explosion propels the cork out of the test tube.

Gases |

Photochemistry |

Reactions

HydrogenReactions and explosions involving hydrogen and its compounds are demonstrated.

Reactions |

Descriptive Chemistry

OxygenReactions and explosions involving oxygen and its compounds are demonstrated.

Oxidation-Reduction ReactionsElectrolysis reactions and the action of nitric acid on iron and copper illustrate the concepts of oxidation and reduction. Also three oxidation-reduction reactions are shown under a microscope.

Reactions of Sulfurous AcidThese demonstrations illustrate the production and effects of sulfur dioxide, a pollutant generated by the burning of sulfur impurities in coal. The sulfurous acid produced by dissolving sulfur dioxide in water is allowed to react with various forms of calcium carbonate found in nature, namely marble, limestone, chalk, and eggshell.

Acids / Bases |

Precipitation / Solubility |

Reactions

Reactions of Nitric AcidThese demonstrations illustrate the production of nitric acid and its reaction with various forms of calcium carbonate found in nature, namely marble, limestone, chalk, and eggshell.

Acids / Bases |

Precipitation / Solubility |

Reactions

MetalsSamples of metals are ignited or heated over a flame, resulting in oxide formation.

Formation of Carbon from CarbohydrateSulfuric acid has a very high affinity for water. It is shown to dehydrate a carbohydrate (sucrose) forming carbon. Sulfuric acid is reduced to sulfur dioxide, which bleaches a rose petal.
In a second experiment, the sulfur dioxide reduces purple permanganate to nearly colorless manganese(II).

Pulsating Electrochemical Reaction: Mercury Beating HeartA drop of mercury in a watch glass is covered with a solution of potassium chromate in concentrated sulfuric acid. An iron nail is positioned so that it nearly touches the mercury. Eventually, the mercury drop starts to beat rhythmically, like a beating heart.